What is secco painting?
Secco (Italian for “dry”, in full fresco secco or a secco) is a technique for making wall paintings on a plaster layer that is already dry and hardened. Because the substrate no longer takes part in the process, the paint must contain its own binder to attach the pigments to the wall.
Difference with fresco:
- In fresco (buon fresco) you paint with pigment in water on fresh, still wet lime plaster. As the lime hardens, the pigments are absorbed into the plaster layer. The painting thus becomes part of the wall and is very durable, but the painter has to work quickly, one section of fresh plaster per session.
- In secco the paint sits as a layer on top of the plaster. The painter can work at a calmer pace, add details and make corrections, and can use pigments that do not tolerate lime.
| Fresco (buon fresco) | Becomes part of the wall and is very durable; work quickly, one section of fresh plaster per session |
|---|---|
| Secco (a secco) | Calmer pace; details and corrections possible; pigments that do not tolerate lime can be used |
Binders used in secco include lime casein, animal glue, egg (tempera) and oil.
Application
In the Middle Ages and the Renaissance, secco was often combined with fresco: the main forms in fresco, the details and certain colours afterwards a secco. Many medieval church paintings in the Netherlands were executed wholly or partly in secco. A famous example of painting on a dry wall is The Last Supper by Leonardo da Vinci in Milan, whose paint layer began to deteriorate soon after completion.
Durability: because the paint layer lies loose on the plaster, secco is more vulnerable than fresco. Moisture, salts and mechanical damage can cause the paint to powder, flake or come away.
Tips if you come across an old wall painting:
- Do not clean or scrape it: when removing later layers of paint or limewash, you can irreparably damage an underlying painting.
- Tackle the moisture: find the cause of rising or penetrating damp before you do anything to the painting.
- Call in a conservator: have the painting investigated and treated by a conservator specialising in wall paintings. In the Netherlands, consultation with the municipality is required for a listed building. Other countries have their own rules; check with your local planning or heritage authority.
- For your own decorative work on an interior wall, lime or casein paint on dry lime plaster is a modern form of the same technique.
Related Terms
- Fresco
- Slaked lime
- Plaster layer
- Leaded glass
- Listed building
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